The present invention relates to microwave devices, and more particularly to a magic tee network having superior amplitude and phase tracking characteristics, lower RF losses and better isolation than conventional stripline networks, and which is smaller and more compact than a waveguide magic-tee network.
Magic-tee devices are well known in the microwave arts. These are four port devices having the characteristic that input power provided at a device input port will be equally divided between two output ports but 180.degree. out of phase.
One common implementation of the magic-tee is as a waveguide magic-tee. Waveguide magic-tee devices are bulky and have a relatively narrow bandwidth.
Another magic-tee implementation is in the form of stripline ratrace hybrids. These devices are generally offer non-symmetrical performance over a relatively narrower bandwidth.
Magic-tees are also implemented in the form of a stripline quadrature coupler with a 90.degree. delay line. These types of devices have the disadvantages of non-symmetrical operation and limited performance over a wide bandwidth.
Other implementations of magic-tee devices include stripline asymmetrical couplers, which have poor phase tracking across a wide frequency band, and microstrip/slotline magic-tees, wherein the respective ports are not shielded from each other.
It would therefore be an advantage to provide a magic-tee device which is compact, wideband and electrically symmetrical.
It would further be advantageous to provide a magic tee device which is physically planar and electrically symmetrical, and wherein each port of the device is shielded from the others.